The use of optical fiber strain sensors to detect the reactionary force on the end effector of a catheter is known. U.S. Patent Application Publication No. 2007/0060847 to Leo et al. (Leo I), assigned to the assignee of the present application, discloses an apparatus and method using fiber Bragg gratings coupled to a deformable body for inferring the magnitude and direction of a reaction force imparted on the distal portion of an end effector. U.S. patent application Ser. No. 11/753,429 to Leo et al. (Leo II), also assigned to the assignee of the present application, discloses an apparatus and method using Fabry-Perot resonators operatively coupled to a fiber optic to infer the magnitude and direction of reaction forces imparted on the distal portion of an end effector. While these devices have advanced the art in terms of resolving the forces applied in touch sensitive operations such as ablation procedures, they lack an integrated way of determining the position or location of the catheter during the procedures. Instead, the position of the catheter and/or end effector within a patient must be determined by an alternative approaches such as fluoroscopy or fMRI.
Position sensing and shape resolution using multiple arrays of fiber Bragg gratings is also known for elongated catheter bodies without an end effector. U.S. Patent Application Publication No. 2007/0065077 to Childers et al. (Childers) and U.S. Patent Application Publication No. 2007/0265503 to Schlesinger, et al. (Schlesinger) disclose the use of fiber Bragg gratings operatively coupled to an elongate flexible body to sense the local strains of the body at a multitude of points, and a method for inferring the shape of the body and a position of the distal portion of the elongated catheter body based on the strain imposed on the fiber Bragg gratings.
A system that enables accurate determination of touching forces on a distal portion in combination with simultaneous accurate position sensing of an elongated surgical manipulator would be welcome.